1. Technical Field
The present invention relates to a light source device and a projector.
2. Related Art
In the past, there has been known a projector provided with a light source device, a light modulation device for modulating a light beam emitted from the light source device to thereby form image light, and a projection optical device for projecting the image light on a target projection surface such as a screen in an enlarged manner. Among these constituents, as the light source device, a configuration provided with a discharge light emitting tube such as a super high-pressure mercury lamp, and a reflecting member (a reflector) for reflecting the incident light from the light emitting tube has been widely adopted.
The discharge light emitting tube has a light emitting section having a roughly spherical shape, and a pair of sealing sections extending from the both ends of the light emitting section in the directions opposite to each other, and in the discharge space inside the light emitting section there are encapsulated a pair of electrodes and a light emitting material such as mercury. When lighting such a light emitting tube, an upper part of the light emitting section becomes an area with the highest temperature, and a lower part thereof becomes an area with the lowest temperature. If the high temperature state of the upper part of such a light emitting section continues, devitrification becomes apt to occur on the one hand, if the difference in temperature between the upper part and the lower part becomes large, blackening becomes apt to occur on the other hand, and thus, the light emitting tube becomes apt to be deteriorated.
Regarding such a problem, there has been known a light source device provided with a rectifying device disposed between the light emitting section and the reflecting member and for flowing the cooling air, which flows along the inner surface of the reflecting member, toward the light emitting section (see, e.g., JP-A-2008-216727 (Document 1)).
The rectifying device described in Document 1 is provided with a pair of rectifying plates for changing the direction of the cooling air, and guides the cooling air flowing along the inner surface of the reflecting member so as to be spooled in the upper side of the light emitting section with one of the pair of rectifying plates.
However, in the rectifying device described in Document 1 mentioned above, there is a problem that some of the cooling air reaching the rectifying device flows laterally along the rectifying plate, and fails to be guided to the light emitting section. Therefore, there has been demanded a configuration capable of more efficiently cooling the light emitting section (in particular the upper part of the light emitting section).